House plants and greenhouse plants need fertilization to realize optimum growth. Such fertilization has been a time consuming, wasteful and inaccurate process. A controlled method of feeding such plants is a long standing need in the home and in industrial greenhouses.
Liquid and powdered fertilizers have been used but are lost through the soil as the plants are continually watered wasting a national resource. There has now been discovered a fertilizer rod composition comprising a polyvinyl alcohol polymer, a plasticizer and a fertilizer, said rod having cold water solubility, is biodegradable, nontoxic and as a rod or composite meters the release of fertilizer into the soil supplying plant nutients on a controlled basis. The rods can be varied in size as to length and cross section and number used to provide exact amount of food to the plant. Such rods are readily stored, handled and used providing low cost systems of fertilization. The rods are inserted into the soil around the plant and gradually dissolve to provide plant food. The danger of overfertilizing are minimized along with the danger of using liquids or powders which are corrosive and toxic.